Background - Platelets are anucleated blood cells and contain various RNA species. We investigated the changes in the whole transcriptome expression profile of platelet concentrates (PC) during storage to explore biological functions and biomarkers in platelet storage damage.
Materials and methods - Platelets were collected by apheresis from eight healthy blood donors and stored from day 0 to day 4. Platelet phenotyping and function analysis were used to detect platelet activity during storage. RNA-sequencing was used to detect changes in expression of mRNA, lncRNA and circRNA in the PC during storage. Gene ontology and KEGG analyses were applied to predict the functional distribution of differential expression of mRNA. Gene set enrichment analysis was used to analyze the differential levels of gene pathways. Finally, polymerase chain reaction (PCR) analysis was performed to verify the expression of three mRNA (POLE2, DCUN1D4, DAD1).
Results - In total, 10,767 mRNA, 2,923 lncRNA and 68,550 circRNA were detected in the PC by RNA-sequencing. The expression levels of 222 mRNA changed significantly from day 0 to day 4 of storage: 58 increased continuously and 145 decreased continuously. Differentially expressed mRNA may be involved in physiological processes such as platelet activation, platelet aggregation, endocytosis, and apoptosis. Expression levels of 1,413 lncRNA were obvious. The levels of 42 species increased and the levels of 28 species decreased. The expression levels of 198 species of circRNA changed significantly, with those of 13 species changing continuously. The differential levels of expression of DAD1, DCUN1D4 and POLE1 mRNA, shown by RNA sequencing, were validated by PCR assay.
Discussion - Changes in mRNA, lncRNA and circRNA during platelet storage may be closely related to platelet apoptosis and physiological functions in the platelet storage lesion. The expression levels of DAD1, DCUN1D4 and POLE1 could be biomarkers to monitor platelet status in PC bags.